The trend in electronic products has been toward smaller sizes, lighter weights, higher speeds, and higher-frequency transmission. Therefore, the trend is toward high-density printed circuit boards. In order to maintain transmission rate and transmission signal integrity, the ideal materials for use in printed circuit boards have a low dielectric constant (Dk) and a low dissipation factor (Df). Since the signal transmission rate is inversely proportional to the square root of the dielectric constant of the substrate material, a suitable substrate material is apt to have a relatively low dielectric constant. Furthermore, since the dissipation factor is directly proportional to the signal transmission loss, suitable substrate material is apt to have a relatively low dissipation factor in order to maintain transmission signal integrity.
In addition, the need for thermal-resistant and flame-retardant materials for use in semiconductor applications is gradually increasing. For example, electronic materials are classified to comply with the UL 94V-0 standard. Conventional materials in a flame-retardant circuit board are mostly an epoxy resin system. In general, an epoxy resin system employs a sufficient quantity of filler in order to enhance flame retardancy. Due to the great amount of filler, the adhesion between the epoxy resin layer and the copper foil may be decreased, thereby reducing the functionality and degrading the reliability of electronic products.
Accordingly, there is a need for a novel resin composition to meet the requirements of high thermal resistance and low dielectric constant, for high frequency circuit boards.